github.com/v2fly/v2ray-core/v4@v4.45.2/testing/servers/tcp/port.go (about) 1 package tcp 2 3 import "github.com/v2fly/v2ray-core/v4/common/net" 4 5 // PickPort returns an unused TCP port of the system. 6 func PickPort() net.Port { 7 listener := pickPort() 8 defer listener.Close() 9 10 addr := listener.Addr().(*net.TCPAddr) 11 return net.Port(addr.Port) 12 } 13 14 func pickPort() net.Listener { 15 listener, err := net.Listen("tcp4", "127.0.0.1:0") 16 if err != nil { 17 listener = pickPort() 18 } 19 return listener 20 }